Production of Esters
- Esters are compounds with an -COOR functional group and are characterised by their sweet and fruity smells
- They are prepared from the condensation reaction between a carboxylic acid and alcohol with concentrated H2SO4 as catalyst
- This is also called esterification
- The first part of the ester’s name comes from the alcohol and the second part of the name comes from the carboxylic acid
- Propanol and ethanoic acid will give the ester propyl ethanoate
Esters are formed from the condensation reaction between carboxylic acids and alcohols
Hydrolysis of Esters
- Esters can be hydrolysed to reform the carboxylic acid and alcohol by either dilute acid or dilute alkali and heat
- When an ester is heated under reflux with dilute acid (eg. sulfuric acid) an equilibrium mixture is established as the reaction is reversible
Ester hydrolysis by dilute acid is a reversible reaction forming carboxylic acid and alcohol
- However, when heated under reflux with dilute alkali (eg. sodium hydroxide) is an irreversible reaction and the ester is fully hydrolysed
- This results in the formation of a sodium carboxylate salt which needs further acidification to turn into a carboxylic acid
Ester hydrolysis by dilute alkali is an irreversible reaction forming a sodium carboxylate salt and alcohol